Vinyl structure having an embossed top layer and a foam base

ABSTRACT

A vinyl structure is made by a specific technique which yields an embossed top layer and a foam base. The embossed top layer is made of a material which fuses and which is embossable at a lower temperature than the base foam. After the two layers are formed, the product is heated to a point which will soften the top layer, but not the foam base and consequently embossing will affect only the top layer.

CROSS-REFERENCE TO RELATED APPLICATION

This is a division, of application Ser. No. 312,813, filed Dec. 7, 1972now U.S. Pat. No. 3,887,409.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention herein is directed to an embossed product and the processof making the product. More particularly, it is directed to a productwhich has an embossed top layer structure and a base foam layer whichhas been unaffected by the embossing operation.

2. Description of the Prior Art

In the floor covering art, it is common practice to make a floorcovering material with a foam backing and an embossed wear layer or toplayer. U.S. Pat. No. 3,196,062, is typical of the techniques utilized toform the above-mentioned product. A backing or a fabric has placedthereon a foamable thermoplastic resin material and then over that isplaced a second thermoplastic resin. The product is subjected to heatand the foamable thermoplastic material is foamed. The thermoplasticresin is normally a nonfoamable material and it is simply fused by theheat. While the total product is still hot, it is then fed to embossingrolls which emboss a pattern in the upper surface of the product.Normally, the embossing penetrates into the foam layer in that the foamlayer receives some deformation as a result of the embossing of the topthermoplastic resin layer.

It is the purpose of the invention herein to provide a product andtechnique for making the same wherein the embossing is done to the toplayer without any impression being transmitted into the foam backing.Without the impression being transmitted into the foam backing, the foambacking will thus be undamaged by the embossing.

SUMMARY OF THE INVENTION

It is desired to deeply emboss the top layer of a vinyl structurecontaining a foam base without the undue crushing or deformation of thefoam base. In the inventive process herein, a bottom foamable materiallayer is metered onto a carrier. On top of this is placed a layer ofembossable vinyl material. Layers are fully fused and/or foamed togetherand cooled. The top layer is then reheated to fusion by top heat andembossed. The top embossable layer is formulated so that it reaches fullfusion at a significantly lower temperature than the fusion temperatureof the bottom foam layer since the top layer is readily embossed with noor little collapse or overblowing of the bottom foam layer.

BRIEF DESCRIPTION OF THE DRAWING

The drawing herein is a cross-sectional view of the product of theinvention herein.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the FIGURE, there is shown the product formed by theinventive process herein. The product shown happens to be a floorcovering material. This structure is provided with a backing 2 whichwould normally be kept with the flooring when it is installed in a home.The product could be used for some purposes other than flooring. It ispossible that it could be made without the backing 2. Under suchcircumstances, the product would be formed wherein the backing would beutilized as a carrier or a separate carrier would be utilized during themanufacturing process. After the product is made, the temporary backingor carrier would be stripped from the finished product.

The main parts of the invention structure herein are the foam backinglayer 4 and the embossable layer 6. The foam backing layer 4 is aconventional foamable thermoplastic resin. It could be the thermoplasticresin set forth in the above-mentioned U.S. Pat. No. 3,196,062, or anyother conventional type foamable material.

The embossable layer 6 may be either a foamable or nonfoamablethermoplastic resin. Herein in the example, the material may be similarto that set forth in above-mentioned U.S. Pat. No. 3,196,062. However,the critical difference between layer 4 and layer 6 is that layer 6 mustbe formed of a material which fuses and is embossable at a lowertemperature than that of layer 4. Consequently, during a subsequentreheating operation when heat is applied on only the layer 6, this layerwill heat to a temperature where it may be readily embossed, while thelayer 4 has not yet reached a temperature where it can be consideredsoft enough for embossing or be heated to a temperature where it isoverblown. That is, it is heated to a point where the blowing agent hascaused the foam material to form and then is heated even further so thatthe foamed thermoplastic material is caused to collapse from the heat.

The inventive technique for making the above product is almost the sameas that set forth in the above-mentioned U.S. Pat. No. 3,196,062. Abacking or carrier 2 receives first the foamable thermoplastic resin.Over top of this is placed either a foamable or nonfoamable embossablethermoplastic resin which fuses at a lower temperature than the layer 4.Both layers are then subjected to heat so that both products are heatedto their full fusion temperature. If both products are foamable, bothproducts are heated to the point that both have foamed. The product isthen cooled. The product is then reheated from the top surface only andit is heated only to the point necessary to soften the top layer so thatit may be embossed. The product is then embossed. Since the foam backlayer 4 has not been heated to its fusion temperature, it will maintainits resiliency and even though temporarily deformed during the actualembossing stage, it will not be permanently deformed by having theembossing temperature collapse the foam structure of layer 4. Theproduct is then permitted to cool and is then available for use as aflooring.

In one specific embodiment of the invention which has been utilized, thefoam back layer 4 has been formed from the following formulation:

                           Parts by Weight                                        ______________________________________                                        Polyvinyl chloride resin - PVC 450 -                                                                   100                                                   Diamond Shamrock                                                             Dioctyl phthalate plasticizer                                                                          70                                                   Epoxidized soybean oil - Admex 710 -                                                                   5                                                     Ashland Oil Co.                                                              Calcium zinc liquid soap - Ferro 95V1 -                                                                4                                                     Ferro Chemical Co.                                                           Limestone                10                                                   Silica (hydrated)        0.75                                                 Titanium dioxide         2.21                                                 Azodicarbonamide - Kempore 60 - National                                                               2.25                                                  Polychemicals Inc.                                                           ______________________________________                                    

The embossable top layer has been formed from the following formulation:

                              Parts by Weight                                                               Foamable                                                                            Nonfoamable                                   __________________________________________________________________________    Polyvinyl chloride resin - Exon 965 - Firestone                                                         100   100                                           Di 2-ethyl hexyl phthalate plasticizer                                                                  50    50                                            Epoxidized soybean oil - Admex 710 - Ashland                                                            5     5                                              Oil Co.                                                                      Calcium zinc liquid soap - Ferro 95V1 - Ferro                                                           5     --                                             Chemical Co.                                                                 Barium, cadmium, phosphite liquid soap - Ferro                                                          --    5                                              5245 - Ferro Chemical Co.                                                    Titanium dioxide          4.0   5.0                                           Silica (hydrated)         1.25  1.0                                           Azodicarbonamide - Kempore 60 - National                                                                2.25  --                                             Polychemicals Inc.                                                           __________________________________________________________________________

The top layer is fusible at a temperature of about 300° F. whereas thefoamable layer will foam and is fused at a temperature of about 400° F.Just prior to the embossing operation, the product is top heated to atemperature of about 290° F. for embossing. This temperature will be lowenough so that the foam backing layer 4 is not heated to its fusiontemperature.

What is claimed is:
 1. A vinyl structure which is composed of a foamback structure and an embossable top layer, both said foam backstructure and said embossable top layer being formed of substantiallythe same composition of material, said embossable top layer beingembossed and those regions of the foam backing which are directly belowthe deeply embossed portions of the embossed top layer being undamagedand without any foam cell structure collapse, said undamaged conditionof the foam backing resulting from the fact that the top layer is formedfrom a plastisol resin which has a lower fusing temperature than theplastisol resin forming the foam backing, said top layer plastisol resinhaving a fusing temperature which is about 300°F. and said foam backinghaving a fusing temperature which is about 100°F. above the fusingtemperature of the top layer plastisol resin.
 2. The structure of claim1 wherein the top layer is also a foamable thermoplastic resin.